考虑质量耦合效应的流体饱和孔隙介质波动方程

利用混合物理论和连续介质力学的基本原理,推导了考虑质量耦合效应的流体饱和弹性孔隙介质的波动方程,并与经典的Biot波动方程进行了对比.结果表明:该文得到的方程包含了Biot波动方程的所有要素,且形式与后者基本相同.比较而言,该文推导过程具有更明确的物理意义,概念也更完整.     

基于改进的灰关联理论定量表征致密砂岩储层微观孔隙结构对储层品质的影响

影响致密砂岩储层品质的因素很多,储层微观孔喉结构是决定致密储层品质好坏的关键因素.以鄂尔多斯盆地姬塬地区长6致密砂岩储层为分析对象,基于高压压汞实验,将灰色系统理论、众数理论和Spearman理论联合,建立优化的灰关联度计算模型,采用优化的灰色关联序定量表征致密砂岩微观孔隙结构参数对储层品质因子的影响,得到各影响因素与...     

超深硬岩地层井壁失稳的动力学分析模型：本征频率和高应力的影响

针对超深致密砂岩地层井壁动力学失稳难题,考虑孔隙流体和硬岩的压缩性、惯性及黏滞耦合作用,建立井筒压力波动条件下井周应力分布公式,建立了超深致密硬岩地层井壁坍塌指数的孔隙弹性动力学模型,分析地层本征频率与高应力对井壁失稳的影响规律。本文提出的孔隙弹性动力学模型预测的地层较传统模型预测的地层更易失稳,且高本征频率、最大地应力高的地层比一般地层更易失稳;揭示了超深硬岩地层井壁突发性失稳力学本质,可为钻井过程中井筒压力控制参数调整提供科学依据。

     

血液灌流吸附剂的研究─—DAC包膜活性炭的制备及性能

本文研制了一种ＤＡＣ包膜活性炭血液灌流吸附剂，对模拟血中中分子物质有很好的吸附能力，对其吸附特性时行了理论探讨。     

双重孔隙渗流作用井眼围岩损伤力学模型研究

考虑双重介质建立了井眼围岩力学模型,考虑井眼围岩岩体为孔隙、裂缝双重介质,将围岩区域分为破坏区、损伤区和弹性区,建立双重介质渗流作用下的井壁围岩不同区域的损伤力学计算模型和井眼损伤区域的计算方法,计算结果表明理论计算模型与有限元模拟结果吻合较好.     

浅析升钟水库右总干渠石爬明渠填方段滑坡形成的原因

本文阐述了升钟水库右总干渠石爬明渠填方段滑坡的地质环境、规模及特征，分析了渗漏对填筑土、粉砂质泥岩C、φ值的影响，论述了红层丘陵区填方输水渠道滑坡形成的原因，计算了孔隙水压力、渗透压力对填方渠堤稳定性的影响，介绍了该区的防渗整治措施。     

砂砾岩油藏渗透系数研究

为了掌握砂砾岩油藏渗流规律,基于砂砾岩中砾和砂含量及其排列方式不同,开展了理论和实验研究。把砂砾岩孔隙度和渗透率设为砾、砂含量的函数,再基于Kozeny-Carman方程建立渗透率与孔隙度和颗粒粒径的函数关系。研究表明,砂砾岩组成及颗粒排列方式是控制砂砾岩渗透系数的主要因素,砂砾岩渗透率与孔隙度为一种线性关系。水驱油实验进一步表明,束缚水饱和度依赖于砂、砾含量,含水上升快,揭示了砂砾岩油藏特有的渗流特点。     

颗粒材料内部滑动变形局部化的离散元模拟

颗粒材料在加载过程中表现出非常复杂的变形性质.在微观尺度上,单个颗粒的运动、单个孔隙胞元内的变形都是非均匀的,但也不是完全随机、没有规律可循的,而是呈现一定结构性的分布,如微带、剪切带等.本文用基于孔隙胞元的离散元方法对颗粒体进行双轴加载数值试验,模拟了以滑动变形表征的变形局部化现象.数值结果发现,对应加载过程中的不同...     

A discrete element model for simulating saturated granular soil

A numerical model is developed to simulate saturated granular soil, based on the discrete element method. Soil particles are represented by Lagrangian discrete elements, and pore fluid, by appropriate discrete elements which represent alternately Lagrangian mass of water and Eulerian volume of space. Macro-scale behavior of the model is verified by simulating undrained biaxial compression tests. Micro-scale behavior is compared to previous literature through pore pressure pattern visualization during shear tests. It is demonstrated that dynamic pore pressure patterns are generated by superposed stress waves. These pore-pressure patterns travel much faster than average drainage rate of the pore fluid and may initiate soil fabric change, ultimately leading to liquefaction in loose sands. Thus, this work demonstrates a tool to roughly link dynamic stress wave patterns to initiation of liquefaction phenomena.     

Separating viscoelasticity and poroelasticity of gels with diferent length and time scales简

Viscoelasticity and poroelasticity commonly coexist as time-dependent behaviors in polymer gels. Engineering applications often require knowledge of both behaviors separated; however, few methods exist to decouple viscoelastic and poroelastic properties of gels. We propose a method capable of separating viscoelasticity and poroelasticity of gels in various mechanical tests. The viscoelastic char- acteristic time and the poroelastic diffusivity of a gel define an intrinsic material length scale of the gel. The experimen- tal setup gives a sample length scale, over which the solvent migrates in the gel. By setting the sample length to be much larger or smaller than the material length, the viscoelasticity and poroelasticity of the gel will dominate at different time scales in a test. Therefore, the viscoelastic and poroelastic properties of the gel can be probed separately at different time scales of the test. We further validate the method by finite-element models and stress-relaxation experiments.